NEED URGENT HELP ANYONE !!!!!!

Ok so on the 11th of September i had unprotected sex (yes i know stupid of me) my boyfriend said he didn't cum but i was still anxious anyways i was so busy i couldn't get the contraceptive pill the day after or for the next 2-4 days. i booked an appointment at the doctors to get tested for a sti and asked my doctor to go on the pill but i'm on lamictal 50g as i have epilepsy so there could be side effects. so we planned for me to go on the implant (rod). She said once i get my period she'll put it in my arm. I went and got the contraceptive pill the day after i saw the doctor so it was 5 days after i had protected sex but it was a stronger dose. so my period was due 6 days ago i still havnet got it. But i've been getting sore breasts and breaking out which i usually get before i get my period. I've read people who are on lamictal have experience getting there period late. I'm still stressing out so much. any advise? my stomach looks kinda big but that's just cause i've been eating unhealthy. I can't get a pregnancy test cause i have no money. I'm also 16 and i don't want to tell my mum. Please no hate i'm just super anxious and worried 😭😭😭😭